Arctic temperatures are rising fast, and permafrost is thawing…. Our collective estimate is that carbon will be released more quickly than models suggest, and at levels that are cause for serious concern.

We calculate that permafrost thaw will release the same order of magnitude of carbon as deforestation if current rates of deforestation continue. But because these emissions include significant quantities of methane, the overall effect on climate could be 2.5 times larger.

Recent years have brought reports from the far north of tundra fires1, the release of ancient carbon2, CH4 bubbling out of lakes3 and gigantic stores of frozen soil carbon4. The latest estimate is that some 18.8 million square kilometres of northern soils hold about 1,700 billion tonnes of organic carbon4 — the remains of plants and animals that have been accumulating in the soil over thousands of years. That is about four times more than all the carbon emitted by human activity in modern times and twice as much as is present in the atmosphere now.

The carbon is locked in a freezer in the part of the planet warming up the fastest (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“). Countless studies make clear that global warming will release vast quantities of GHGs into the atmosphere this decade. Yet, no climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.

The new analysis is based on a survey of “41 international scientists, listed as authors here, who publish on various aspects of permafrost.” Yet even this new paper is conservative. Their worst-case scenario appears to be derived from the out-of-date 2007 IPCC report, whereby Arctic warming “only” hits 7.5°C [13.5°F] by 2100. And the new article further assumes temperature is then held constant for the next 200 years.

Carbon emission (in billions of tons of carbon a year) from thawing permafrost.

The main difference is the Nature article projects considerably higher Permafrost Carbon Flux (PCF) after 2100 — up to 865 billion tonnes CO2-eq by 2300.

The stunning conclusion of the NOAA/NSIDC paper was:

The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate…. [Our] estimate may be low becauseit does not account for amplified surface warming due to the PCF itself….

We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.

Again, that assumed all the PCF came out as CO2. The new study finds:

Across all the warming scenarios, we project that most of the released carbon will be in the form of CO2, with only about 2.7% in the form of CH4. However, because CH4 has a higher global-warming potential, almost half the effect of future permafrost-zone carbon emissions on climate forcing is likely to be from CH4. That is roughly consistent with the tens of billions of tonnes of CH4 thought to have come from oxygen-limited environments in northern ecosystems after the end of the last glacial period.10

And because of the much higher warming impact of methane over shorter time frames, even this low percentage level of methane means that over a 20 year period, the warming from CH4 will actually be higher than that of CO2.

The Nature article concludes:

Our group’s estimate for carbon release under the lowest warming scenario, although still quite sizeable, is about one-third of that predicted under the strongest warming scenario.

… our survey outlines the additional risk to society caused by thawing of the frozen north, and underscores the urgent need to reduce atmospheric emissions from fossil-fuel use and deforestation. This will help to keep permafrost carbon frozen in the ground.

Duh.

For those who want more background on the permafrost, the news release is quite good. Here’s a final comment by the lead author:

“Even though we’re talking about a place that is very far away and seems to be out of our control, we actually have influence over what happens based on the overall trajectory of warming. If we followed a lower trajectory of warming based on controlling emissions from the burning of fossil fuels, it has the effect of slowing the whole process down and keeping a lot more carbon in the ground,” Schuur said. “Just by addressing the source of emissions that are from humans, we have this potential to just keep everything closer to its current state, frozen in permafrost, rather than going into the atmosphere.”

Duh, again.

One last point. This article only looked at the land-based permafrost. Let’s remember the study from last year:

Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting: NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”Methane and carbon release from the Arctic is the most dangerous amplifying feedback in the entire carbon cycle. This research finds a key “lid” on “the large sub-sea permafrostcarbon reservoir” near Eastern Siberia “is clearlyperforated, and sedimentary CH4 [methane] is escaping to the atmosphere.”

Time‘s Bryan Walsh concludes his piece on the new article, “Scary stuff. But at least things are back to normal on the climate science beat: vaguely apocalyptic.”

The climate science is only apocalyptic if we keep ignoring it.

The people out there who think R&D or an energy quest is going to stop us from multiple catastrophes are deluding themselves and others. We need to start aggressive mitigation now as every major independent study concludes.

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Good Post! BTW, how many times to we have to read: “Yet, no climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.” Yah think it is about time for someone to do a study?

Yeah, no kidding….between the clathrates and the permafrost this has been crying out for study for many years.

I hope the 5th IPCC Assessment includes includes methane feedback too but that seems like a long shot at this point – the current timeline for the 5th IPCC Assessment shows the Assessments start to be written by the summer of next year (2012) – the window of time where we can get such a methane feedback report (and its implications) included seems to be rapidly closing for the 2013 / 2014 IPCC assessment (the next IPCC assessment would probably be in the 2020’s when we’ll be living the effects of increased methane emissions).

Back in November 2010 Natalia Shakhova and Igor Semilitov presented to the Department of Defense Environmental Research Program a slide show indicating that the ESAS is now venting 3.5 billion tonnes of methane per year.

If 10% of ESAS methane were released over 20 years GW would increase by a factor of 40, resulting in mass extinction.

I firmly believe that, with the meltdown in Arctic volume, methane escape, and economic inertia, that runaway warming is now inevitable.

You fellows here will probably hate me for this but given the apocalyptic scenario we’re headed for I would suggest that once a mass die off of humanity begins and runaway warming is clear, we implement a geoengineering program.

SCAS, I don’t hate you but your ideas border on the absurd. At what point do those crazy ideas begin to WHAT???..cool the planet; put a cork in the negative feedbacks; cause the summer Arctic ice to return to pre-industrial extent. And, that is what I think

Only a crisis, real of perceived, brings about real change. The public cannot fathom that such catastrophic climate change is possible in the near term, nor can they fathom human extinction.

With the corporate takeover of America’s political system complete, and the immense levels of denial, especially among the fossil intensive countries, no change will occur until mass starvation (>500 000 000) sets in. Even if the public wants change, corporations will not allow it. With the peak oil cliff on the horizon, society is unlikely to get off dirty fuels.

Call me a cynic – people won’t change especially since media outlets now work for corporations. Once runaway warming sets in, all bets are off – the public will scream out for geoengineering.

scas, I agree with your depiction of the current state of affairs, but how does geo-engineering save us? Surely geo-engineering merely lessens the symptoms, while the underlying pathology steadily worsens. And what is a ‘sun shroud’? I’d say that the amount of money required would be better spent on a massive program of renewable energy development and installation, plus efforts to reforest as much of the planet as possible, and a technological drive to find some means to physically remove greenhouse gases from the atmosphere. With human existence now (indeed it has been for years) at stake, we could first of all redirect the two or three trillion wasted by the world on ‘defence’ every year. Defence personnel might prefer saving the planet to destroying it as well.

We can argue until the sun burns out about what we should be doing under various scenarios, but as for what we will do, I hate to say it, but I think scas’ crystal ball has it right.

I long ago concluded that we were locked into a geoengineered future, what I started calling “living measured lives on a managed planet”. There is simply far too much momentum pushing us in that direction, from carbon already in the atmosphere to political, economic, and psychological latencies we have to overcome to the wrong kind of physical infrastructure we’re still building at a breakneck pace.

Add to that runaway freight train the growing evidence that the tracks ahead of us include a very long and steep downhill grade (i.e. the permafrost carbon plus the methane hydrates) and it’s really hard to see how we’ll avoid not just experimenting with geohacking but using it as a last, desperate resort.

The ultimate bottom line is that we’re faced with a decision: Do we take steps now to act in our own best interest, steps that are very unpopular with some very powerful entities, or do we wait until the pain of inaction is so great that it overcomes the best efforts of those entities to lie to us and buy themselves a few more years of obscene, murderous profits?

————————————-

As for the basic finding regarding carbon stores, I’ve long thought that as we learned more about the paleohistory of the Earth System we would find out that our worst enemy was geography. Look at a map of the north polar region, and you see something almost perfectly constructed to create whipsaw climate changes. The most northern area is all open water, which means it will be a positive feedback via Arctic amplification/albedo flip. But there’s also a huge amount of land not too far south, land that will grow lots of biomass in very warm periods, which will then freeze over as soon as a cooling event starts. Whenever the next warming period starts, whether due to orbital perturbations or hairless apes burning fossil fuels, albedo flip starts early and boosts the initial warming signal, and then all that trapped carbon (plus undersea hydrates) starts to cut loose, and we’re off to the races again.

Sadly, the evidence is accumulating that my half-a**ed, layman’s theory (read: wild guess) might be more right than wrong. I really hope I’m wrong, but it doesn’t feel that way as the drumbeat of “it’s worse than we thought” discoveries continues.

We know what to do, and how to do it, and why (to survive), yet we allow a tiny, psychotic, elite to stop us. That’s the ‘To be or not to be..’ question. Whether it is better in reality to allow the malevolence of the few to destroy us all, or take up arms (metaphorically)and save our skins. When I see Osbourne in the UK destroying environmental protection to the benefit of rich rentiers, with relish, when I see Harper proceed with tar sands with fiendish insistence, when I see the Tea Party rabble vow to destroy the EPA and when I see our own politicians boast of coal mining going on ‘for generations’ and export ports to be expanded by twenty times, I cannot but think that these are creatures either ignorant and stupid beyond belief, or far, far, worse, and unambiguously unfit intellectually and morally to govern. They have to go.

This is crucial information, and needs to be aggressively delivered to all of our major political and media centers. If this information is ignored (likely), this negligence should be publicized through nontraditional media outlets.

We have known for some time that increased Arctic methane releases are inevitable, and are already under way, based on Mauna Loa measurements. The consequences of inaction are not acceptable. The media’s excuses are no better than someone deciding to not worry about incoming nuclear weapons, since they aren’t here yet.

Letters to editorial boards and pleas to TV network headquarters are always going to be brushed off by the major companies. This is criminal negligence by any objective standard, even if the consequences are in the future. Maybe it’s time to occupy Rockefeller Center, as well as the headquarters of Viacom and Time Warner. Protestors should be armed with this post.

“There’s more organic carbon in northern soils than there is in all living things combined; it’s kind of mind boggling.”

Northern soils hold around 1,700 billion gigatons of organic carbon, around four times more than all the carbon ever emitted by modern human activity and twice as much as is now in the atmosphere, according to the latest estimate. When permafrost thaws, organic material in the soil decomposes and releases gases such as methane and carbon dioxide.

“In most ecosystems organic matter is concentrated only in the top meter of soils, but when arctic soils freeze and thaw the carbon can work its way many meters down, said Abbott, who studies how carbon is released from collapsed landscapes called thermokarsts — a process not accounted for in current models. Until recently that deep carbon was not included in soil inventories and it still is not accounted for in most climate models.

“Recent years have brought reports from the far north of tundra fires, the release of ancient carbon, CH4 bubbling out of lakes and gigantic stores of frozen soil carbon. The latest estimate is that some 18.8 million square kilometres of northern soils hold about 1,700 billion tonnes of organic carbon
— the remains of plants and animals that have been accumulating in the soil over thousands of years. That is about four times more than all the carbon emitted by human activity in modern times and twice as much as is present in the atmosphere now.”

You have to be very careful here, because there is (always) some confusion when it comes to ‘billions’ between the U.K. interpretation of that magnitude, and the U.S. interpretation. And since that figure is expressed in ‘tonnes’, I suspect it is referring to the U.K. version of the measurement. If I understand correctly:

U.K. billion = 1 million * 1 million = 10 ^ 12 = U.S. *trillion*

So the original poster said “1,700 billion gigatons” which is quite a bit too much in any valid unit of measure, whereas you said “Nope. It’s 1,700 tonnes, not gigatons.” which is too little because that much could almost be buried in my own back garden. And Nature said: “about 1,700 billion tonnes”

Now… since mankind currently emits about 30 gigatonnes of CO2 annually, I’m betting that the 1,700 figure is in gigatonnes, and that is still very scary indeed because that represents 1700/30 = 56.67 years worth of emissions at our current rate. And CH4 is a much more potent GHG over a 20-year time period than CO2, as has already been pointed out :-\

Yes, AND, the values you provide for methane’s Global Warming Potential (GWP), or 25 times CO2 over 100 years and 72 over 20 years, is from the 2007 IPCC Fourth Assessment. Subsequent to the development of that data, NASA has updated methane’s GWP to account for indirect aerosol effects. The current methane GWP, accounting for aerosols, is 33 times CO2 over 100 years and 105 times over 20 years. See Drew Shindell, “Improved Attribution of Climate Forcing Emissions,” 326 Science 716 (2009). The implications are exceedingly disturbing.

The forewarned release of 380 billion tons of CO2 equivalent from the Arctic before 2100 is a similar amount to eleven to thirteen years of anthropogenic CO2 emissions at the 2008 rate of 29 – 32 billion tons of CO2 per year.

Somehow, having an 89 year time line still lulls me away from what is already happening and likely to happen within the NEXT eleven to thirteen years.

Any story or report that speaks of 2100 is a diversion. That is far away, in the ‘long-term’ in which we will all be dead. It pushes off vital decisions into the never-never and is a mechanism to delay action. If things proceed as they are, by 2100 humanity will have been reduced to a mere shadow of its current numbers and our ‘civilization’ will be one with Nineveh and Tyre (don’t tell them that in Tyre).

As BA said, we need multiple reports and associated climate models that incorporate thawing permafrost and clathrate methane feedbacks so we can get a better picture of just what the situation is we’re facing – obviously its going to be a whole lot worse than what we know at this point.

I seem to remember a topic during this last year where it seemed very likely methane feedbacks wouldn’t make it into the 2013 / 2014 IPCC report (contributor selection perhaps) and we’d have to wait till the 6th assessment (presumably in the 2020’s before its inclusion). Joe seems to be saying there’s still a chance we may see something in the 5th Assessment which is good.

It seems the speed of climate change is moving so rapidly that it is threatening to exceed the ability of the scientific community to forecast all of its important pieces (methane emission feedbacks from clathrate and permafrost melting in particular) prior to those events actually occurring.

“I seem to remember a topic during this last year where it seemed very likely methane feedbacks wouldn’t make it into the 2013 / 2014 IPCC report”

Then, why in the heck do we need a 5th Assessment, at its appointed hour, if it does not include thorough treatment of methane feed backs. It is not as if IPCC has to meet a publisher’s deadline. The ARSs are becoming just a tad meaningless because time is our worst enemy and IPCC has a rigid 4 year clock to punch regardless of the vital new information it could include in #5.

John – I share your concern. The I(G)PCC reports are provided to the public as the full scientific consensus, when they are nothing of the sort. Every government has a veto over every line of text. What we are given is only as much as the govt.s of Saudi Arabia, Canada, Venezuela etc are willing to allow.

I fear that there is also a pre-emptive influence by such censorship, as I hear nothing of harsh conflicts over the inclusion of so critical an issue as the feedbacks.

What we now need, urgently, is a new ‘separation of powers’, not only of those of Commerce and State, but also those of Science and State.

In short, we urgently require an “Inter-Academy Panel on Climate Destabilization” [IAPCD], reporting annually to the UN General Assembly, not to closed-door sessions with government hacks. Starting in 2012.

So how many scientists have the courage of their convictions to help manifest this change ?

I agree, and believe that the IPCC’s time has passed, for the reasons stated. It’s too slow and too equivocal. Scientific organizations can provide much better data. The question is whether they are willing to do it, and vociferously defend it in public.

IPCC served its purpose, and it’s time to move on. With independent science, we’ll also get better reports on some of the really bad IPCC sections- Forestry, in particular. And a legitimate scientific document would not include political scientists such as Roger Pielke, Jr.

Yes we need better models but more importantly we need to improve public policy making to deal with the fact that we will never have complete “certainty” in modelling climate change. That does not mean that uncertainty is an excuse not to act. It means that we do not have the luxury of waiting until all the “i’s have been dotted and the t’s crossed” since by that point no amount of actions on our part can alter the outcome. Conducting an expected value analysis based on different emissions scenarios would clarify that.

Personally I suspect we are 10 to 20 years away from passing a “fail safe” position when it comes to the climate change trajectory.

Certainty is bollocks, bollocks concocted by the denialist genocidaires to confuse the proles, delay action and protect their money and power. I know that I’m going to die, but I can’t say, with certainty, when. We know the climate Hell is coming, but exactly when is anybody’s guess, but it is getting closer by the hour and by the reports of new disasters. Yet the political ghouls do nothing.

If there is 1,700 billion tons loosely locked in the arctic soils/permafrost and the East Siberian Arctic Shelf methane hydrates (or clathrates) are holding 1,500 billion tons, doesn’t that add up to 3,200 billion tons total in the arctic region? – and, if so, can we expect a two-for-one payback as the feedback loops around?

Also, back in September it was reported that a number of Russian and American scientists left hurriedly on a 45 day expedition to the Arctic region. Is this their report or will that be forthcoming.

Report of September 2011 expedition will be out around April next year. This refers to earlier work.

I await it with some alarm, if only because, by my calculations, it was organised in about 2 weeks. Now to get a research ship readied and crew and 30 scientists assembled and prepared in 2 weeks in August – the main Northern Hemisphere holiday period – denotes some urgency. One quote I saw, from a member of the expedition, mentioned finding “thousands” of methane vents where they’d previously only found “a few”. That seems to me to imply about a two orders of magnitude increase in methane production.

If this is as serious as it could be, I’ve little doubt that preliminary reports are already on Obama & Putin’s desks!

That said, all the information I’ve seen so far is from Tass and Novosti news agencies (apart from panicky bloggers) and I’m old enough to remember when they were both totally subservient propaganda mouthpieces of the CPSU (Communist Party of the Soviet Union) so I’m inclined to take what they say with a pinch of salt – especially with Putin in the driving seat again.

Years ago it was said not to say the outcome because if humanity didn’t forestall the outcome as the outcome happens humanity would then only panic.
I think the outcome is now.being said to be happening.

The newspapers talk a little about the outcome with stories about storms. They are getting better about showing the why of the storms. But, that advertising section just leaves it up to people to panic when hit with a storm. Don’t really know that business will just get over their dislike of storms; but story is this coming year we will see many more than this year. Maybe they think it’s a storyline to an upcoming movie?

And the Arctic sea ice loss in summer will send the warming signal further inland. Further melting that permafrost. It is all but inevitable that clathrates will warm enough after the ice is gone in summer over the East Siberean continental shelf.
I will have to bring up the topic of Civilizational Collapse at Christmas dinner with mom,elder sister, little niece… They will tolerate the conversation for a minute or two and then condescendingly agree that “may be yes but do you really think that you are smarter than all the respected and rich folks in governments and you don’t even have a regular white collar job. What have you done with your education? Throw it all away in transition towns? Go plant a garden? You must be joking.”
My mother understands intuitively that there is something deeply wrong about the way society operates but she only shrugs this feeling off with – “you won’t be able to defend your garden from angry city mobs, even if it all happens, go get a life.”
And I understand with my reason that so many great scientists can’t be wrong and seeing all the evidence around the world. But may be we somehow can magically still just have our peace and no hunger on christmas. Another 10-15 years untill she dies of natural causes may be.
And then there is this Peak Oil conversational thread and you can not bring up the topics of apocaliptic nature in polite company more than once. I hate to be a wet blanket at a party and not being taken seriously. The only hope is that collapse is gradual and not like “The Road” scenario. Merry Christmas. Let’s cherish this fragile peace while it lasts

Yes, I can relate to this. It seems that, in polite company – even among those who (in theory) accept the evidence for catastrophic climate change – it’s not considered “nice” to bring up the subject. It so depresses the mood at a dinner party.

About the only person I can talk freely to about my fears is my therapist – and he’s paid to listen!

Without having access to the full report it is hard to see its coherence.

While it does quantify the methane fraction of carbon emissions, this seems implausibly precise at 2.7% – with no ‘error bars’ – for a phenomenon occurring over several hundred years, with unknown interactions, threshold effects, etc.

It is also remarkably precise given the reluctance of previous papers to attempt even a general estimate of its proportion – as with the NSIDC paper’s notable exclusion of any such quantification.

Moreover that precise 2.7% figure is belied by the image at the top of the post, which is one of many of researchers igniting emission plumes rising from ex-permafrost. There have been no statements I’ve seen that only a fraction of these emission plumes are ignitable, so it can reasonably be inferred that their flammability is the norm. The emission plume shown is mixing with airborne oxygen before being able to burn, and in air methane has lower and upper flammable-limit concentrations (LFL & UFL) of 5% and 15% respectively. Thus the methane fraction of the unmixed plume must be well above 5% if it is still to be flammable after mixing with air. If it were above 15% it would become flammable once it mixed with enough air for each CH4 molecule to meet with two O2 molecules. (CH4 + 2O2 = CO2 + 2H2O).

Yet perhaps the paper explains why the precise 2.7% figure can be justified, despite widespread observations of at least three-fold concentrations by field researchers ?

The proposed CO2e outcomes also seem questionable, particularly given the bizarre assumption that global temperature magically stabilizes in 2100.

As Peter Anderson noted above: “The current methane GWP, accounting for aerosols, is 33 times CO2 over 100 years and 105 times over 20 years. See Drew Shindell, “Improved Attribution of Climate Forcing Emissions,” 326 Science 716 (2009).” Given that the paper used the AR4 assessment of warming, it might be inferred that the same outdated assessment of methane’s GWP was also used, but whether for a 20-yr or 100-yr horizon has yet to be reported this side of the paywall.

The reliability of the projected rate of carbon emissions due to melting must reflect warming including that due to previous permafrost emissions, which in turn reflects both the percentage and the GWP value of methane outputs. Confidence in that projected rate rests on the accurate evaluation of each link of the chain.

In short, while the paper plainly tries to be more explicit than the recent NSIDC account, its reportage thus far raises as many questions as it answers. Some further details would be very welcome.

I do not have a subscription to access the article. Did this study include estimates of the microbial metabolism at the near-freezing temps of former permafrost soils? Certainly they will outgas their carbon eventually, but I think I’ve heard that the microbes’ metabolic rates in these cold soils are so low that there is a multi-decades-long delay between thawing and the inevitable outgassing. So I’m curious what the report had to say about estimating the period between thaw and release… anyone?

Given the greatly increasing rainfall over permafrost tundra shown on the NCAR charts of global precipitation-change this century
(Joe’s done at least two posts on them IIRC)
we can expect much of the permafrost melt to be assisted by rainfall and waterlogging – (acting as heat transport from warm air-masses above to the sub-surface ice-face) – as is already showing up in images of immense new wetlands of ex-permafrost in Siberia.

Presumably remote sensing can quantify the percentage of ex-permafrost areas that are already waterlogged or actually submerged.

So how does this new (fully peer reviewed) report justify its surprisingly precise estimate of only 2.7% of permafrost carbon being emitted as methane ?

This has implications for use of natural gas fuel – enthusiasts claim it has half the CO2 emissions of coal, but using Shindell’s figures for the GWP of Methane implies that a 2% leakage rate to the atmosphere would increase global warming compared to coal. With fracking the rate could be substantially higher. The front end loading of methane could produce substantial aggressive warming in coming decades.

The quotes from the Schuur et al paper posted above appear inconsistent once they’re explored mathematically. For all Joe and I differ on some matters of interpretation (such as over Obama’s motivation for his de-jure adoption of Bush climate policy) I’ve yet to see anything but scrupulous accuracy in his reporting of new scientific papers. Equally, this paper was peer-reviewed for ‘Nature’, which should imply a total consistency of data and text, unless some anomaly has occurred.

From the post, quoting the paper:

– “Across all the warming scenarios, we project that most of the released carbon will be in the form of CO2, with only about 2.7% in the form of CH4. However, because CH4 has a higher global-warming potential, almost half the effect of future permafrost-zone carbon emissions on climate forcing is likely to be from CH4.”
– “Our collective estimate is that carbon will be released more quickly than models suggest . . .”
– “We calculate that permafrost thaw will release the same order of magnitude of carbon as deforestation if current rates of deforestation continue. But because these emissions include significant quantities of methane, the overall effect on climate could be 2.5 times larger.”
– “The new analysis finds the permafrost releases up to 380 billion tonnes of CO2 equivalent by 2100.”

Rather than being quicker, this is far slower than the ~100GtC the NSIDC study projected, and less than a third of the ~178GtC that deforestation on current rates (~2.0GtC /yr) would release by 2100. Also, it is nowhere near 2.5 times the warming effect of that level of deforestation; in fact it is only about 1.86 times the warming if the 55.65 GtC were all emitted as CO2.

One point where the 380 GtCO2 and 2.7% CH4 figures do tally with the text is in “almost half the effect” being from methane (47.8%); this share is reduced to near 41% if methane’s CO2e value is set at (the outdated) 25 on 100 years, while the required carbon output rises to only ~63.0GtC. (Using the 20-year CO2e value of 105 gives a warming share of 74.4% and an output of only 27.3GtC).

While the 2.7% methane projection will doubtless be subject to much further research, particularly as ex-permafrost waterlogging expands, it is worth applying it to the NSIDC curve of permafrost carbon emissions under the 105 CO2e value on 20 years (the logical choice given the feedback dynamic) to assess its implications.

That curve shows about 100GtC of output by 2100 which would amount to 1,395.25 GtCO2e under these factors.
It also shows ~0.54GtC output in 2020, which under these factors equates to 7.53 GtCO2e, which is about 23.9% of present annual anthro-CO2 output.
At its peak at 2100 that curve shows ~1.6GtC /yr output, which under these factors equates to 22.32 GtCO2e, which is about 70.9% of present annual anthro-CO2 output.

Even without accounting the several other interactive mega-feedbacks, it seems that permafrost’s projected outputs would have to shrink by at least an order of magnitude if success in the rapid control of anthro-GHG outputs is to be any more than entirely necessary but utterly insufficient to resolve the predicament.